1. Field of the Invention
This invention relates to improved clenched-on fittings which are placed onto the bung housing member of a cask or container for beverages which are dispensed from the container by a pressurized gas or pump. Such fittings are known and comprise a valve unit which is secured within an upstanding bung housing integral with the cask. The fitting has an extractor tube extending to the base of the container and through which liquid is extracted by pressurized gas applied to the top of the liquid in the cask. The valve unit co-operates with a head fitting which can be engaged by means of a coupling with the upstanding bung housing whereby ports are opened by the head fitting operating on the valve unit to allow gas to pass into the container head space and to allow beverage to flow from the extractor tube outlet ports through the head fitting to a remote dispense point.
2. Description of the Prior Art
Various valve fittings are known and these are secured within the bung hole housing by a screw threaded connection or by using circlips or other means affording removal. Removal is required for cleaning and to provide replacement of worn and damaged components in the unit, especially the rubber seal at the head of the fitting.
Relevant prior art is disclosed in French Pat. No. 1468211 and in British Pat. No. 930015. A disadvantage inherent in the embodiments disclosed in these patents is that unauthorized removal of the fitting containing the valve unit is relatively easy using simple tools and hence undetected pilfering, adulteration and topping-up of part empty containers can occur. There is also additional cost involved in providing screw or other machined connections and the material thickness of the upstanding bung hole sleeve has to be increased to accommodate the threading depth.
In applicant's prior published British Application Serial No. 2058264A, a fitting is disclosed wherein the valve unit is integrated with the bung hole housing with only the extractor tube being removable by use of a special tool after upsetting and removal of the head seal assembly.